METHOD AND APPARATUS FOR RAPID SUB-DIFFRACTION INFRARED IMAGING AND SPECTROSCOPY AND COMPLEMENTARY TECHNIQUES

• US 20180180642A1
• Filed: 11/29/2017
• Published: 06/28/2018
• Est. Priority Date: 11/29/2016
• Status: Active Grant

• Current Assignee: Photothermal Spectroscopy Corp.
• Original Assignee: Anaysis Instruments Corporation
• Inventors: Shetty, Roshan, Kjoller, Kevin, Prater, Craig
• Granted Patent: US 10,969,405 B2
• Time in Patent Office: Days
• CPC Class Codes: G01N 2021/1725 Modulation of properties by light, e.g. photoreflectance
• CPC Class Codes: G01N 21/1717 with a modulation of one or more physical properties of the sample during the optical investigation, e.g. electro-reflectance
• CPC Class Codes: G01N 21/31 Investigating relative effect of material at wavelengths characteristic of specific elements or molecules, e.g. atomic absorption spectrometry G01N21/72 takes precedence
• CPC Class Codes: G01N 21/3563 for analysing solids; Preparation of samples therefor
• CPC Class Codes: G01N 21/65 Raman scattering
• CPC Class Codes: G01Q 30/02 Non-SPM analysing devices, e.g. SEM [Scanning Electron Microscope], spectrometer or optical microscope
• CPC Class Codes: G01Q 30/025 Optical microscopes coupled with SPM

Abstract

Methods and apparatus for performing chemical spectroscopy on samples from the scale of nanometers to millimeters or more with a multifunctional platform combining analytical and imaging techniques including atomic force microscopy, infrared spectroscopy, confocal microscopy, Raman spectroscopy and mass spectrometry. For infrared spectroscopy, a sample is illuminated with infrared light and the resulting sample distortion is read out with either a focused UV/visible light beam and/or AFM tip. Using the AFM tip or the UV/visible light beam it is possible to measure the IR absorption characteristics of a sample with spatial resolution ranging from around 1 μm or less to the nanometer scale. The combination of both techniques provides a rapid and large area survey scan with the UV/visible light and a high resolution measurement with the AFM tip. The methods and apparatus also include the ability to analyze light reflected/scattered from the sample via a Raman spectrometer for complementary analysis by Raman spectroscopy. Using a UV/vis source or IR source at higher intensity it is possible to thermally desorb material from a sample for analysis by mass spectrometry. The AFM tip can also be heated to desorb material for mass spec analysis at even higher spatial resolution.

Claims

1-21. -21. (canceled)

22. An apparatus for rapidly characterizing a sample with infrared radiation on a submicron scale, the apparatus comprising:

a source of infrared radiation configured to illuminate a sample with a beam of infrared radiation to create an infrared illuminated area;

a source of ultraviolet-visible (UV-vis) radiation configured to illuminate at least a region of the infrared illuminated area of the sample with a beam of UV-vis light;

a collector configured to collect as collected light at least a portion of the UV-vis light that is at least one of scattered, refracted, and reflected from the sample;

a receiver configured to analyze the collected light as indicative of an infrared absorption of the region of the infrared illuminated area;

a scanner configured to create relative motion between the sample and at least one of the beam of infrared light and the beam of UV-vis light to measure the infrared absorption of the sample over a scan area that includes a plurality of locations on the sample; and

an atomic force microscope subsystem configured to measure a response of a cantilever probe over at least a portion of the scan area.

23. The apparatus of claim 22, wherein the apparatus is configured to use at least the infrared absorption at the plurality of locations on the sample to construct a spatially resolved map of infrared absorption of at least a portion of the sample.

24. The apparatus of claim 22, wherein the source of infrared radiation illuminates the sample at plurality of wavelengths and the receiver analyzes the collected light as indicative of an infrared absorption spectrum for at least one location on the sample.

25. The apparatus of claim 22, wherein the response of the cantilever probe comprises a response to the beam of infrared radiation.

26. An apparatus for rapidly characterizing a sample with infrared radiation on a submicron scale, the apparatus comprising:

a source of infrared radiation configured to illuminate a sample with a beam of infrared radiation to create an infrared illuminated area;

a source of ultraviolet-visible (UV-vis) radiation configured to illuminate at least a region of the infrared illuminated area of the sample with a beam of UV-vis light;

a collector configured to collect as collected light at least a portion of the UV-vis light that is at least one of scattered, reflected and refracted from the sample;

a receiver configured to analyze the collected light as indicative of an infrared absorption of the region of the infrared illuminated area; and

a Raman spectrometer configured to analyze the collected light to analyze a Raman response of the sample.

27. The apparatus of claim 26, wherein the Raman response is used to construct at least one Raman spectrum from at least one region of the sample.

28. The apparatus of claim 26, wherein the receiver configured to analyze the infrared absorption and the Raman response substantially simultaneously.

29. The apparatus of claim 26, wherein the infrared absorption and the Raman response are determined at a sub-micron resolution.

30. An apparatus for rapidly characterizing a sample with infrared radiation on a submicron scale, the apparatus comprising:

a source of infrared radiation configured to illuminate a sample with a beam of infrared radiation to create an infrared illuminated area;

a source of ultraviolet-visible (UV-vis) radiation configured to illuminate at least a region of the infrared illuminated area of the sample with a beam of UV-vis light;

a collector configured to collect as collected light at least a portion of the UV-vis light that is at least one of scattered, reflected and refracted from the sample; and

a receiver configured for confocal optical microscopy and further configured to analyze the collected light as indicative of infrared absorption of the region of the infrared illuminated area of the sample.

31. The apparatus of claim 30, wherein the receiver comprises at least one of a confocal aperture and a pinhole.

32. An apparatus for rapidly characterizing a sample with infrared radiation on a submicron scale, the apparatus comprising:

a broadband source of infrared radiation configured to illuminate a sample with a beam of infrared radiation to create an infrared illuminated area;

a source of ultraviolet-visible (UV-vis) radiation configured to illuminate at least a region of the infrared illuminated area of the sample with a beam of UV-vis light;

a collector configured to collect as collected light at least a portion of the UV-vis light that is at least one of scattered, reflected and refracted from the sample; and

a receiver configured to analyze the collected light as indicative of infrared absorption of the region.

33. The apparatus of claim 32, wherein the broadband source comprises at least one of a globar and a thermal source.

34. The apparatus of claim 32, further comprising a modulator configured to modulate the beam of infrared radiation.

35. The apparatus of claim 34, wherein the modulator is configured to modulate the beam of infrared radiation at a frequency in excess of 10 kHz.

36. An apparatus for rapidly characterizing a sample with infrared radiation on a submicron scale, the apparatus comprising:

a source of infrared radiation configured to illuminate a sample with a beam of infrared radiation to create an infrared illuminated area;

a source of ultraviolet-visible (UV-vis) radiation configured to illuminate at least a region of the infrared illuminated area of the sample with a beam of UV-vis light;

a collector configured to collect as collected light at least a portion of the UV-vis light that is at least one of scattered, reflected and refracted from the sample; and

a receiver configured to analyze the collected light as indicative of an infrared absorption of the sample;

wherein the receiver comprises at least one of a position sensitive detector and an array detector; and

wherein the infrared absorption of the sample is measured with a spatial resolution of less than or equal to 1 micrometer.

37. An apparatus for rapidly characterizing a sample with infrared radiation on a submicron scale, the apparatus comprising:

a source of infrared radiation configured to illuminate a sample with a beam of infrared radiation to create an infrared illuminated area;

a source of ultraviolet-visible (UV-vis) radiation configured to illuminate at least a region of the infrared illuminated area of the sample with a beam of UV-vis light;

a collector configured to collect as collected light at least a portion of the UV-vis light that is at least one of scattered, reflected and refracted from the sample; and

a receiver configured to analyze the collected light as indicative of an infrared absorption of the sample;

wherein at least one of the collector and the receiver includes a filter to block at least a portion of the UV-vis light.

38. The apparatus of claim 37, wherein the filter comprises a central obscuration.

39. An apparatus for rapidly characterizing a sample with infrared radiation on a submicron scale, the apparatus comprising:

a source of infrared radiation configured to illuminate a sample with a beam of infrared radiation;

a first focusing optic configured to focus the beam of infrared radiation to form an infrared illuminated region of a sample;

a source of ultraviolet-visible (UV-vis) radiation configured to illuminate a sub-region of the sample with a beam of UV-vis light;

a second focusing optic configured to focus the beam of UV-vis light at the sub-region of the sample, wherein the sub-region at least partially overlaps the infrared illuminated region;

a collector configured to collect as collected light at least a portion of the UV-vis light that is at least one of scattered, reflected and refracted from interaction of the beam of UV-vis light with the sample;

a receiver configured to analyze the collected light and provide an indication of an infrared absorption of the sub-region.

40. The apparatus of claim 39, wherein the first focusing optic has a numerical aperture of at least 0.7.

41. The apparatus of claim 39, wherein the second focusing optic comprises a parabolic mirror.

42. The apparatus of claim 39, wherein the beam of UV-vis light illuminates a sub-region of the sample that is smaller than the infrared illuminated area.

43. The apparatus of claim 39, wherein the collector comprises an objective that is further configured to focus at least one of the beam of infrared radiation and the beam of UV-vis light on the sample.

44. The apparatus of claim 39, wherein the collector comprises an objective, and wherein the source of UV-vis radiation and the objective are arranged such that the beam of UV-vis light is focused on the sample by the objective and the collected UV-vis light is collected by the objective.

45. A method for rapidly characterizing a sample with infrared radiation on a submicron scale, the method comprising:

illuminating a sample with a beam of infrared radiation to create an infrared illuminated area;

illuminating at least a region of the infrared illuminated area of the sample with a beam of ultraviolet-visible (UV-vis) light;

collecting as collected light at least a portion of the UV-vis light that is at least one of scattered, refracted, and reflected from the sample;

analyzing the collected light to determine an infrared absorption of the region of the infrared illuminated area;

creating relative motion between the sample and at least one of the beam of infrared light and the beam of UV-vis light to measure the infrared absorption of the sample over a scan area that includes a plurality of locations on the sample; and

measuring a response of a cantilever probe over at least a portion of the scan area with an atomic force microscope.

46. The method of claim 45, further comprising constructing a spatially resolved map of infrared absorption of at least a portion of the sample using at least the infrared absorption at the plurality of locations on the sample.

47. The method of claim 45, wherein:

illuminating the sample with a beam of infrared radiation includes illuminating the sample at plurality of wavelengths; and

analyzing the collected light includes analyzing the collected light as indicative of an infrared absorption spectrum for at least one location on the sample.

48. The method of claim 45, wherein the response of the cantilever probe comprises a response to the beam of infrared radiation.

49. A method for rapidly characterizing a sample with infrared radiation on a submicron scale, the method comprising:

illuminating a sample with a beam of infrared radiation to create an infrared illuminated area;

illuminating at least a region of the infrared illuminated area of the sample with a beam of ultraviolet-visible (UV-vis);

collecting as collected light at least a portion of the UV-vis light that is at least one of scattered, refracted, and reflected from the sample;

analyzing the collected light to determine an infrared absorption of the region of the infrared illuminated area; and

analyzing the collected light to detect a Raman response of the sample.

50. The method of claim 49, further comprising constructing at least one Raman spectrum from the Raman response.

51. The method of claim 49, further comprising analyzing the infrared absorption and the Raman response substantially simultaneously.

52. The apparatus of claim 49, wherein the infrared absorption and the Raman response are determined at a sub-micron resolution.

53. A method for rapidly characterizing a sample with infrared radiation on a submicron scale, the method comprising:

illuminating a sample with a beam of infrared radiation to create an infrared illuminated area;

illuminating at least a region of the infrared illuminated area of the sample with a beam of ultraviolet-visible (UV-vis) light;

collecting as collected light at least a portion of the UV-vis light that is at least one of scattered, refracted, and reflected from the sample;

analyzing the collected light at a receiver configured for confocal optical microscopy, wherein analyzing the collected light includes determining an infrared absorption of the region of the infrared illuminated area.

54. The method of claim 53, wherein the receiver comprises at least one of a confocal aperture and a pinhole.

55. A method for rapidly characterizing a sample with infrared radiation on a submicron scale, the method comprising:

illuminating a sample with a beam of infrared radiation from a broadband source of infrared radiation to create an infrared illuminated area;

illuminating at least a region of the infrared illuminated area of the sample with a beam of ultraviolet-visible (UV-vis) light;

collecting as collected light at least a portion of the UV-vis light that is at least one of scattered, refracted, and reflected from the sample;

analyzing the collected light to determine an infrared absorption of the region of the infrared illuminated area; and

analyzing the collected light to detect a Raman response of the sample.

56. The method of claim 55, wherein the broadband source of infrared radiation comprises at least one of a globar and a thermal source.

57. The method of claim 55, further comprising modulating the beam of infrared radiation at a modulator.

58. The method of claim 57, wherein the modulator is configured to modulate the beam of infrared radiation at a frequency in excess of 10 kHz.

59. A method for rapidly characterizing a sample with infrared radiation on a submicron scale, the method comprising:

illuminating a sample with a beam of infrared radiation from a source of infrared radiation to create an infrared illuminated area;

illuminating at least a region of the infrared illuminated area of the sample with a beam of ultraviolet-visible (UV-vis) light;

collecting as collected light at least a portion of the UV-vis light that is at least one of scattered, refracted, and reflected from the sample; and

analyzing the collected light at a receiver having a position sensitive detector and an array detector to determine an infrared absorption of the region of the infrared illuminated area, wherein the infrared absorption of the infrared illuminated area is measured with a spatial resolution of less than or equal to 1 micrometer.

60. A method for rapidly characterizing a sample with infrared radiation on a submicron scale, the method comprising:

illuminating a sample with a beam of infrared radiation to create an infrared illuminated area;

illuminating at least a region of the infrared illuminated area of the sample with a beam of ultraviolet-visible (UV-vis) light;

collecting as collected light at least a portion of the UV-vis light that is at least one of scattered, refracted, and reflected from the sample;

analyzing the collected light at a receiver to determine an infrared absorption of the region of the infrared illuminated area; and

blocking at least a portion of the UV-vis light with a filter arranged at at least one of the collector and the receiver.

61. The method of claim 60, wherein the filter comprises a central obscuration.

62. A method for rapidly characterizing a sample with infrared radiation on a submicron scale, the method comprising:

illuminating a sample with a beam of infrared radiation;

focusing the beam of infrared radiation at an infrared illuminated region of the sample with a first focusing optic;

illuminating at least a region of the infrared illuminated area of the sample with a beam of ultraviolet-visible (UV-vis) light;

focusing the beam of UV-vis light at a sub-region of the sample that partially overlaps the infrared illuminated region with a second focusing optic;

collecting as collected light at least a portion of the UV-vis light that is at least one of scattered, refracted, and reflected from the sample; and

analyzing the collected light to determine an infrared absorption of the region of the infrared illuminated area.

63. The method of claim 62, wherein the first focusing optic has a numerical aperture of at least 0.7.

64. The method of claim 62, wherein the second focusing optic comprises a parabolic mirror.